1. Field of the Invention
This invention relates to germicidal compositions, and more particularly relates to an iodine carrier having polyvinylpyrrolidone blocks in a polyurethane.
2. Background
Iodine is a well-known germicide with activity against a wide range of bacteria and viruses, and much effort has been directed to finding satisfactory vehicles for its administration. Some polymeric materials form complexes with iodine. These complexes, termed iodophors, are used commercially with a sponge or brush for germicidal cleaning or scrubbing. Often, such implements are included in a kit of materials which may also include other items useful for patient preparation, such as towels, gloves, nail cleaners and the like. Polyurethanes are disclosed as iodophors by Shelanski, U.S. Pat. No. 3,235,446 and by LaVeen in U.S. Pat. No. 4,381,380.
Another polymer well-known to form an iodophore is polyvinylpyrrolidone (PVP), and PVP iodophores have been extensively used as germicidal preparations. The structure of PVP-iodine is discussed by Schenck et al. in the Journal of Pharmaceutical Sciences 68, 1505 (1979).
A blend of PVP and polyurethane is applied to a substrate surface as a hydrophilic coating in U.S. Pat. No. 4,642,267 to Creasy et al. Creasy et al. is not concerned with iodine delivery.
A copolymer of PVP with a hydroxyethyl acrylate is disclosed by Winn in U.S. Pat. No. 4,373,009. The copolymer is applied as a lubricious coating to a substrate surface by first priming the surface with an isocyanate and then reacting the isocyanate with the copolymer. Winn et al. is also not concerned with iodine delivery.
Lorenz et al. in U.S. Pat. No. 4,769,013 discloses an interpenetrating polymer network complex of P-I and polyurethane which may be used in the form of a coating or foam.
Prior art iodophors used for iodine delivery suffer from various deficiencies such as instability leading to loss of iodine titer, tissue sensitivity due to the corrosive effects of iodine, and rapid water leachability of the iodophor.
While the above disclosures have improved the delivery of iodine, further improvements, particularly an iodine carrier which delivers the iodine slowly, is needed. The present disclosure is directed to fulfillment of this need.